Step 1

Preheat oven to 180C/160C fan-forced. Grease a 16cm x 26cm (base) slice pan. Line base and sides with baking paper, extending paper 2cm above all edges of pan.

Step 2

Combine flours, sugar and custard powder in a bowl. Make a well. Add butter. Mix to combine. Press mixture evenly into prepared pan, levelling with the back of a spoon. Bake for 25 minutes or until golden and just firm to touch. Cool for 25 minutes.

Step 3

Gently spread jam over base. Bake for 10 minutes. Using picture as a guide, arrange marshmallows on top of jam. Bake for 5 minutes or until marshmallows are puffed. Sprinkle with coconut. Cool completely.

Step 4

Cut slice into bars. Serve.